Sept 9 - Abdominal, Back and Shoulder Region

Question 1

Name the two main groups of abdominal muscles

Answer 1

Anterior abdominal wall in front of the column (flexion).

Posterior abdominal wall behind the column (extension).

Question 2

What is the importance of abdominal muscles?

Answer 2

They’re stabilizers that support the trunk and lower back

Question 3

What function do the anterior abdominal muscles serve?

Answer 3

They serve a protective function
They cause movement of the trunk
They allow for changes in size of the cavity

Question 4

Anterior abdominal muscles are innervated by:

Answer 4

intercostal nerves

Question 5

Name the four anterior abdominal muscles

Answer 5

External abdominal oblique
Internal abdominal oblique
Transverse abdominal muscle (transversalis)
Rectus abdominus muscle

Question 6

Describe the external abdominal oblique

Answer 6

It’s the outer most muscle on the anterior wall

It pushes pressure from the front inwards

Question 7

Describe the internal abdominal oblique

Answer 7

It runs perpendicular to the external to the external oblique
It’s deep to external oblique
It functions with the external oblique to power “same side rotation”

Question 8

Describe the transverse abdominal muscle

Answer 8

It connects the ribcage and pelvic bone
It forms a front platform
It flattens the lordotic curve of the spine
It stabilizes the anterior abdominal wall

Question 9

Describe the rectus abdominus muscle

Answer 9

Most superficial pair of muscles run up either side of the mid-line of the abdomen
Identified by their bulging segments created by connective tissue divisions called Tendinous
Divides muscle into 4 sections (8-pack)

Question 10

Name the three posterior abdominal wall muscles

Answer 10

Erector spinae
Iliacus muscle
Psoas major muscle

Question 11

Describe the erector spinae group

Answer 11

Large column of muscle on either side of the vertebral column
Important for extension of the spine, but it also works against gravity to control trunk flexion (bending over)
It is often described as a single muscle, but it comprised of three muscles

Question 12

Name the three muscles comprising the erector spinae group

Answer 12

Iliocostalis
Longissimus
Spinalis

Question 13

Describe the quadratus lumborum

Answer 13

It powers lateral flexion of the lumbar spine

Stabilizes the twelfth rib against the action of the diaphragm during inspiration

Question 14

What is the iliopsoas?

Answer 14

The term that refers to the psoas major and the iliacus. It was given because they share a common tendon.

Question 15

Desribe the iliopsoas

Answer 15

The psoas major and iliacus muscles are deep to the abdominal contents adjacent to the vertebral column and within the pelvic cavity. Together they power hip flexion and are innervated by the femoral nerve. They also stabilize the back (important for climbing stairs)

Question 16

What is the rule of 3, regarding the shoulder girdle

Answer 16

It is comprised of 3 bones, 3 joints and 3 ligaments.

Question 17

What is the role of the shoulder girlde

Answer 17

It represents the only attachment of the appendicular skeleton (arm) to the axial skeleton (trunk)

Question 18

Name the three bones of the shoulder girlde

Answer 18

Clavicle (aka the collar bone)
Scapula (aka the shoulder blade)
Humerus (aka the arm)

Question 19

Describe the clavicle

Answer 19

Superficial, “S” shaped bone that acts like a strut (keeps shoulders back and arms at side). Medial third is convex, lateral third is concave (anteriorly).
It defines the broadness of shoulders.
Functions: force absorption, dissipation of force & rotation of the scapula in abduction

Question 20

Describe the scapula

Answer 20

Spade-like, broad based bone. It’s thin, flat, triangular with 3 borders
There is NO attachment to chest wall
It’s held against the ribs by muscles

Question 21

Name the three borders that comprise the scapula

Answer 21

The medial border runs along the vertebral column
The lateral border
The superior border

Question 22

What is the acromiom process?

Answer 22

It’s the most lateral section of the scapula

It’s the part that’s in direct contact with the clavicle - forms a joint called the AC joint

Question 23

What is the glenoid fossa?

Answer 23

Part of the scapula that articulates with the humerus - forms the shoulder joint aka GH joint

Question 24

Describe the humerus

Answer 24

It’s a typical long bone (shaft and 2 enlarged ends)
The proximal end (aka head of the humerus) articulates with the glenoid fossa of the scapula (only about one third of the head is in contact with the scapula)

Question 25

Name the three joints of the shoulder girlde

Answer 25

The sternoclavicular joint (SC joint) The acromioclavicular joint (AC joint) The gleno-humeral joint (GH joint aka shoulder joint)

Question 26

Describe the sternoclavicular joint

Answer 26

It's between the medial clavicle and clavicular notch of the sternum It's a synovial joint - saddle type Movement occurs in a multi axial plane Important for assessory motions

Question 27

Give examples of assessory motions

Answer 27

Rolling, spinning, gliding, translatioj

Question 28

Describe the arcromioclavicular joint

Answer 28

Palpable, rounded eminence on lateral shoulder (point of the shoulder) Lateral clavicle articulates with acromion process (spine of scapula) Plane type synovial joint supported by thick ligaments It allows for the rotation of clavicle on acromion. This is where should "separations" occur

Question 29

Describe the gleno-humeral joint

Answer 29

Articulation between head of humerus and glenoid of scapula Multi-axial ball & socket type synovial joint Freely movable but structurally unstable because very little of humeral head (1/3rd) is in contact with fossa at any one time Glenoid is deepened by a fibrocartilaginous ring (labrum) and stabilized by strong ligaments by increasing contact area

Question 30

Describe the movements, as well as the planes in which they move, of the GH joint

Answer 30

Flexion and extension (sagittal plane) Abduction and adduction (coronal plane) Medial and lateral (transverse plane)

Question 31

Describe scapulothoracic articulation

Answer 31

It's not a true joint because the scapula is not attached by ligaments to the thoracic cage but rather is free floating within a complex of muscle attachments. It's responsible for overhead activity. There is 1° of scapular movement for every 2° of GH movement

Question 32

Describe scapulhumeral rhythm

Answer 32

Movement of the scapula relative to movement of the humerus 1° of scapular movement for every 2° of GH movement. Abduction: 60% of GH joint, 40% of ST joint

Question 33

Name the three movements of the shoulder girdle

Answer 33

Elevation/Depression Protraction/Retraction Horizontal Abduction/Adduction

Question 34

What is circumduction

Answer 34

A composite movement (a bunch of movements added together)

Question 35

Name the three types of muscles acting on the shoulder girdle

Answer 35

Thorax to humerus Thorax to scapula/clavicle Scapula/clavicle to humerus

Question 36

Name the two thorax to humerus muscles

Answer 36

Latissimus dorsi | Pectoralis major

Question 37

Describe the pectoralis major

Answer 37

Large, superficial muscle of the chest that forms the anterior wall of axilla Has 2 heads: clavicular head, which attaches to the medial, anterior clavicle, and sternal head, which attaches to sternum and costal cartilages of first 6 ribs Innervated by lateral and medial pectoral nerves

Question 38

Name the functions of pectoralis major

Answer 38

Functions to power should flexion, adduction and medial rotation (ie. bear hug) It can break your fall (reverse pushup)

Question 39

Describe the latissimus dorsi

Answer 39

Large, superficial, broad, diamond shaped muscle of the back Forms posterior wall of axilla Arises from thoracolumbar fascia of low back, inserts proximal humerus Innervated by thoracodorsal nerve

Question 40

Name the functions of latissimus dorsi

Answer 40

Involved in shoulder extension | Secondary motions: medial rotation, adduction

Question 41

Name the five thorax to scapula/clavicle muscles

Answer 41

``` Trapezius Rhomboid major & minor Serratus anterior Pectoralis minor Sternocleidomastoid ```

Question 42

Describe the trapezius

Answer 42

Large, superficial, triangular muscle that runs from base of the skull all the way down to middle of spine and extends to outer edge of accromium It acts on the scapula, not the shoulder joint There are three sections: upper section (neck), middle fibres and lower fibres

Question 43

Name the function of the trapezius, by section

Answer 43

The upper section is responsible for scapular elevation/rotation, as well as side flexion (unilateral) or extension (bilateral) The middle section is responsible for scapular retraction The lower section is responsible for pulling the medial end of the scapular spine down, rotating glenoid fossa upward and it is important to facilitate raising the arm over head

Question 44

Describe the rhomboid major and minor. What are their functions

Answer 44

Deep to trapezius. It runs from vertebral column to scapula. It runs obliquely down and laterally. It is innverated by dorsal scapular nerve. It functions to retract the scapula Minor is superior to major

Question 45

Describe serratus anterior

Answer 45

"Serrated" digitations on side of chest Extends from chest to vertebral border of scapula, running between thorax & scapula Innervated by long thoracic nerve

Question 46

Name the functions of serratus anterior

Answer 46

Protracts scapula, and functions to stabilize scapula to posterior wall of thorax (prevents winging of scapula)

Question 47

Describe the pectoralis minor. Name its functions

Answer 47

Positioned deep to pectoralis major muscle Actively protracts of scapula (powers reach beyond reach) Innervated by the medial pectoral nerve

Question 48

Describe sternocleidomastoid

Answer 48

Heavy cord like muscle on lateral aspect of the neck | Innervated by accessory nerve (CN XI)

Question 49

Name the functions of sternocleidomastoid

Answer 49

Diverse functions: - contract together (left and right): head and neck flexion - contract unilaterally: tilts chin up and rotates to the opposite side

Question 50

Name the two scapula/clavicle to humerus muscles

Answer 50

``` Deltoid Rotator cuff (SITS) muscles ```

Question 51

Name the four rotator cuff muscles

Answer 51

Supraspinatus Infraspinatus Teres minor Subscapularis

Question 52

Describe the deltoid

Answer 52

Round muscle on top of shoulder, provides bulk of shoulder Forms "U" around the shoulder - 3 distinct heads: anterior, middle, posterior Innervated by axillary nerve

Question 53

Name the functions of the 3 heads of the deltoid

Answer 53

Anterior: shoulder flexion Middle: shoulder abduction Posterior: shoulder extension

Question 54

Describe the rotator cuff

Answer 54

Intrinsic muscles of shoulder that are critical for GH joint stability Comprised of four separate muscles (SITS) to originate from scapula to attach to superior humerus

Question 55

Name the function of the SITS muscles

Answer 55

Supraspinatus: abduction of shoulder Infraspinatus: lateral rotation of shoulder Teres minor: lateral rotation of shoulder Subscapular: medial rotation of shoulder